List of bones to file, is it possible?
So here's the plan:


to import all the armatures into 1 file
to run a script to compare them between each other and export the names of bones they have in common.




Importing (several options):


Just CtrlC, CtrlV from a file to another.
Or ShiftF1 to append an object. Navigate to a .blend file, select Object, and pick the armature object.




After all the armatures are in the same scene, switch to Scripting screen layout.


you can select it from the top menu bar (you should be in the Default screen now)
or you can use  CtrlLeft Arrow and CtrlRight Arrow to switch between the screens.


In the Text editor, make a new text file and paste the code in:

import bpy

bone_names = []
for armature in [ob for ob in bpy.data.objects if ob.type == 'ARMATURE']:
    for bone in armature.data.bones:
        bone_names.append(bone.name)

common_names = set([name for name in bone_names if bone_names.count(name) &gt; 1])

print(common_names)


Run the script, it will print the output into the Console window (Window > Toggle System Console).

If you want to print it into a text-file or json-file that's easy too just give me a file-path and I'll edit the script.